The present invention relates to novel pharmaceutical compositions of high analgesic activity and more particularly to pharmaceutical compositions which contain as effective analgesic agent a 5-phenyl-1H-2,3-dihydro-1,4-benzo diazepine compound of the following FORMULA I ##STR2## or physilogically compatible acid addition salts thereof. In said Formula I
R.sub.1 indicates hydrogen or lower alkyl, PA1 R.sub.2 indicates hydrogen, lower alkyl, or lower alkanoyl, PA1 R.sub.3 indicates hydrogen or halogen, and PA1 R.sub.4 indicates halogen. PA1 R.sub.2 indicates hydrogen, lower alkyl, or lower alkanoyl, PA1 R.sub.3 indicates hydrogen or halogen, and PA1 R.sub.4 indicates halogen. PA1 the substituent R.sub.4 ' indicates halogen or hydrogen, and PA1 the substituent R.sub.1 ' indicates lower alkyl, PA1 as they are obtained by acylation of the corresponding 2-hydroxy-1,4-diamino propane compounds, are subjected to cyclization in a manner known per se by reaction with phosphorus oxychloride. In this manner, a mixture of isomeric compounds of Formula IIIa and IIIb are obtained: ##STR5##
The invention furthermore pertains to the method of treating humans and animals with said compounds as an analgesic agent.
The benzo diazepine compounds of Formula I used as highly effective analgesic agents in the pharmaceutical compositions according to the present invention are comprised by the 5-phenyl-1H-2,3-dihydro-1,4-benzo diazepine compounds which carry in the 2-position a substituted methyl group, as described in U.S. Pat. Nos. 3,998,809, 4,096,141, 4,098,786 and 4,244,869. Said compounds possess the central nervous system influenzing properties and more particularly possess anxiolytic and tranquilizing properties.